DEL MAR >> Track officials might as well rename the $300,000 Del Mar Futurity the Bob Baffert Juvenile, seeing as though the 61-year-old Hall of Fame trainer has made the Grade I race his own personal playground since saddling Silver Charm for a victory in 1996.

Baffert’s American Pharoah, a son of Pioneerof the Nile, took the lead shortly out of the gate under Victor Espinoza and cruised to a 4 3/4-length victory over 15-1 longshot Calculator on Wednesday as Del Mar concluded its 75th summer season in front of an on-track crowd of 11,136.

The ridgling became only the second maiden to win Del Mar’s signature race for juveniles, joining Go West Young Man, who won the race in 1977.

Baffert, who won this race seven consecutive years (1996-2002), has won the stake a record 12 times overall. It’s a long way back to runner-up D. Wayne Lukas, who has won the race three times.

“It worked out well,” Baffert assistant Jimmy Barnes said. “I told Victor in the paddock that the rail seems to be golden today, to just break and go. And he did. And he didn’t stop.”

Baffert wasn’t at Del Mar to watch his newest 2-year-old standout, who went postward as the 3-1 second choice. He left the saddling duties to his assistant

“He just had to get home,” Barnes said of Baffert.

Espinoza hadn’t even seen American Pharoah before he hopped aboard in the paddock. The two-time Kentucky Derby winner was impressed.

“He has everything to be an excellent horse,” Espinoza said.

It wasn’t quite as easy as it might have appeared, but Espinoza was confident as he turned for home in the seven-furlong test on Polytrack.

“He broke a little bit slow and I just encouraged him to take the lead,” he said. “As soon as he took the lead he was in high speed, cruising around there.

“I had to ride him a little bit harder because he was lugging in a little bit. He’s a baby and I wanted to teach him to keep going. I want him moving all the way to the wire.”

Baffert, reached by telephone, said American Pharoah was one of his top 2-year-olds heading into the meeting but acted up in the post parade before his career debut here on Aug. 9 and finished fifth in a field of nine.

“After that my wife Jill looked at me and said, ‘That’s one of your best 2-year-olds? It’s going to be a long summer,’” Baffert said.

Baffert also gave Espinoza pre-race instructions on the phone earlier in the day.

“Baffert called me this morning and he said whatever you do I want you to take him to the lead and go from there,” he said.

It was not one of Baffert’s typically strong meets. Third in the trainer standings last summer with 23 victories, he finished with only 12 this year and the Futurity was his only Grade I win. He also won the Grade II San Diego Handicap with Fed Biz.

“We finished the meet strong, and that’s what we planned to do,” Barnes said.

It was Espinoza’s fourth Futurity victory and first since 2006 aboard Horse Greeley. He didn’t even ride in last year’s running, but the horse who finished sixth, California Chrome, ended up taking Espinoza to the Kentucky Derby winner’s circle.

“I discovered California Chrome here last year, so you never know,” he said.

American Pharoah, who carved out fractions of 22.72, 45.23 and 1:08.95, finished the race in 1:21.48 — the second fastest running ever behind Declan Moon’s 1:21.29 in 2004 since the race’s distance was shortened from a mile to seven furlongs in 1993. American Pharoah’s Futurity time was the fastest since Del Mar switched to Polytrack in 2007.

“He ran so well the other day (in the Best Pal), that race might have taken a lot out of him,” jockey Corey Nakatani said of the favorite. “He’s a big colt and he might need a little more time between.”